Radio grid and filament spacer



W. J. SKINNER RADIO GRID AND FILAMENT SPACER June 5, 1928. 1,672,233

Filed Nov. 14, 1925 Patented June 5, 1928.

WALTER J. SKINNER,

1,612,233 PATENT OFFICE.

OI BLOOHFIELD, NEW JERSEY, ASSIGNOB 'IO HIMSELF AND FRANK J. KENT, OF NEW YORK, N. Y.

RADIO GRID AND FILAMENT SPACER.

Application fled November 14, 192 5. Serial No. 68,954.'

This invention relates to a spacing element adapted to maintain the grid and fila ment of a radio tube in correct spaced relation to each other andto the plate.

These parts must be accurately placed when the tube is assembled, and the tube will function properly only so long as they remain in proper position. The operation of initially spacing the parts is tedious and delicate, as the parts are small and diflicult to control, and the spacing is not lon maintained under the shocks and jars o' transporation and use.

The object of the present invention is to rovide a spacer that will facilitate assemly and permanently secure the parts in correct relation. V

In the accompanying drawing forming a part of this specification, there is' shown by way of illustration a practical embodiment of the invention. Fig. 1 is a perspective view of a flare tube assembly showing the spacer in position.

Fig. 2 is a longitudinal section through Fig. 1.

Fig. 3 spacing elements.

Fig. 4 is a cross section taken in line 4:4: of Fig. .1.

'Referring to the drawings more particulaa'ly, the flare tube 5 is .shown as carrying sealed in its upper end the posts 6, 7, 9, 10, 13, 14 and 15. The plate element 8 is mount-- on the extreme end posts 6 and 7. The posts 9 and 10 extend within the plate element and carry fastened to their upper ends the grid posts 11 and.12, which carry the grid, 19. Posts 13 and 14. also extending within the plate, are adapted to carry hooks for securing the lower ends of the filament 18, the upper end of which is supported by a hook 17 mounted on the post 15 which extends outside the plate.

Ordinarily the and 15 have no support other than the tube 5,- but they must maintain the grid and filament in place within very close limits to insure optimum results from the tube, and since these posts are of relatively light stock they are difficult to assemble and easily be come displaced. The present invention avoids these difiiculties by providing a spacer 16 made of'mica, or similar insulating material, having holes punched therein to represent accurately the proper relative is a plan view of several of the positions of posts 6, 7, 11, 12 and 15. This spacer is placed in position, thereby moving the posts to proper spaced relation before the filament hook is applied to the upper end of post 15.

After the spacing element has been assembled over the ends of the posts the hook 17 is attached to the end of post 15 and the filament 18 is then placed in position.

The spacer remains permanently in place, thereby preventing any of the supporting posts rom moving out of position, and since the spacer is made from insulating material it bhas no effect upon the operation of the to e.

- Attention is called to the fact that the spacer is V-shaped, being notched to provide suitable clearance about the filament and having its apex extended to support post 15 which lies outside of the plate 8. Fig. 3 shows how nicely this configuration lends itself to the operation of stamping from sheet material, the spacers nesting together very closely so that there is practically no waste.

I claim: T

1. In a flare tube assembly, a flare tube, supporting posts mounted at one end in said tu e and carrying a plate, grid-supporting postsmounted at one end said tube and .extending within said plate, a filament-supporting. post mounted at one end in said tube and extending without said plate, and a spaced mounted on the ends of said posts opposite the flare tube.

2. In a flare tube assembly, a flare tube. supporting posts mounted at one end in said tube and carrying a plate, grid-supporting posts mounted at one end in said tube and extending within said plate, a filamentsupporting post mounted at one end in said tube and extending without said plate, and

. a spacer mounted on the ends of said posts long slender posts 11, 12

mounted at one end in said tube and carry-- ing a grid within said plate, a filament post mounted at one end in said tube and extending without said plate, a hook attached to the upper end of the filament post, a filament mounted onsaid hook, and a spacer mounted on the ends of said posts opposite the flare tube and having a cut-out portion providing a clearance about said filament.

4. In a flare tube assembly, a flare tube, supporting posts mounted at one end in said tube and carrying a plate, grid post-s mounted at one end in said tube and carrying a grid Within said plate, a filament post mounted at one end in said tube and extending without said plate, a hook attached to the upper end of the filament post, a filament mounted on said hook, and a V-shaped spacer mounted on the ends of said postsand resting on the plate, said spacer having a clearance about said filament.

In testimony whereof I aifix my signature.

\VALTER J. SKINNER 

